The invention relates to a device for controlling cylinder disconnection in internal combustion engines of the type having at least one control arrangement including a switchable element for valve actuation of the valves and permitting in one of its two switching states an actuation of the valve concerned, and having transmission devices which, in dependence on the switching state of the control arrangement, transmit the cam rise produced by the camshaft to the valve via the switchable element, and with a control unit acting on the switching arrangement.
In the partial load region of an Otto engine cycle, there is only a comparatively low efficiency of the engine because of low turbulence in the combustion chambers, low cylinder filling, and high charge exchange losses. A possibility for increasing the efficiency in the partial load region includes reducing the throttling of the cylinders. However, cylinder disconnection is preferably used, in which individual combustion chambers of the engine are disconnected for a predetermined time.
Thus from DE 196 28 024 A1 an internal combustion engine is known which has a camshaft and, for each gas exchange valve, a transmission device by means of which the cam stroke can be transmitted to the gas exchange valve. The cylinders of the internal combustion engine are divided into two cylinder groups, an actuator being allocated to each group and permitting the actuation of the gas exchange valves in only one of its two switching states.
In such a solution, all the valves of a cylinder group are changed over at a given instant, leading to the control becoming effective only after passing through the switch over window allocated to the valve concerned, and to diverse problems in changing over the valve drives.